Abstract

Positron annihilation spectroscopy has been used to study the vacancy-type defects produced in filmsgrown by metalorganic chemical vapor deposition on different sapphire orientations. Znvacancies are the defects controlling the positron annihilation spectra at room temperature. Close to the interface their concentration depends on the surface plane of sapphire over which the ZnOfilm has been grown. The Znvacancy content in the film decreases with thickness, and above it is independent of the substrate orientation.